Crutch.



PATENTED AUG. 6,1907.

M. J. DUNKEL.

` CRUTGH. APPLICATION FILED ILPKIB, 1907.

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@fl Ma wi/tmwaeof MARK JONES DUNKEL, OF NEW BLOOMFIELD, PENNSYLVANIA.

CRUTCH.

Specification of Letters Patent.

Patented Aug. 6, 190'?l Application filed April 13. 1907. Serial No.368,113.

To all whom it may concern:

Be it known that I, MARK JoNns DUNKEL, a citizen of the United States,residing at New Bloomfield, in the county of Perry and State ofPennsylvania, have invented a new and useful Crutch, of which thefollowing is a specification.

The invention relates to improvements in crutches.

The object of the present invention is to improve the construction ofcrutches, and to provide a simple and comparatively inexpensive one,designed particularly for use in winter and having means for presentingeither a plurality of spikes, or a cushion to the supporting surface toprevent the crutch from slipping 011 ice, slippery pavements and similarsurfaces, or to avoid injuring the carpet or floor of an apartment orthe like.

A further object of the invention is to provide a crutch of thischaracter, in which it will be unnecessary to perforate the cushion ofrubber, or other material, so that the saine will not be weakened or itseffectiveness and durability impaired. With these and other objects inview, the invention consists in the construction and novel combinationof parts hereinafter fully described, illustrated in the accompanyingdrawing, and pointed out in the claims hereto appended; it beingunderstood that various changes in the form, proportion, size and minordetails of construction, within the scope of the claims, may be resortedto without departing from the spirit or sacrificing any of theadvantages of the invention.

ln the draw-ingz-Figure 1 is an elevation of a crutch, constructed inaccordance with this invention. Fig. 2 is an enlarged longitudinalsectional view of the central portion of the same, Fig. 3 is a sectionalview, taken substantially on the line x--x of Fig. 2, the key beingarranged for insertion in the opening of the cam. Fig. 4 is an enlargedsectional view of the lower portion of the crutch. Fig. 5 is a planview. Fig. 6 is a detail view of the screw and washer for retaining thekey in engagement with the cam.

Like numerals of reference designate corresponding parts in all thegures of the drawing.

1 designates a crutch, designed to be constructed of wood or any othersuitable material and to be manufactured in various sizes to suit thesize or weight of the person by whom it is to be used. The crutch isprovided in its lower portion 2 with a longitudinal bore or opening 3,and it has a metallic ferrule 4, secured to its lower end. The metallicferrule 4 is provided with an upper interiorly threaded socket 5 for thereception of the lower end 6 of the crutch, the lower end being slightlyreduced and threaded to fit the socket 5 and theouter faces of the partsbeing preferably flush, as shown. The said ferrule is also provided witha lower depending socket 7, forming a tubular guide for a socket orholder S and having an enlarged lower rim or peripheral portion 9 onwhich are mounted spurs 10.

The spurs or projections 10, which are pointed for engaging ice andother slippery surfaces, are provided with threaded shanks 11, which arescrewed into suitable threaded bores or perforations of the enlargedportion or rim of the lower socket 7. The spurs or projections, whichare arranged in an annular series and which may be of any desirednumber, are removable to enable new spurs and projections to besubstituted for those in the crutch, when the same become worn or dull.

The socket or holder 8, which slides vertically in the lower guidingportion of the ferrule 4, is interiorly threaded to receive acylindrical cushion or block l2 of rubber, leather, or other suitablematerial, which is adapted to be moved downward and to project beyondthe spurs or projections to prevent the latter from coming in contactwith a Hoor, carpet or other surface to avoid tearing, scratching,marring, or otherwise injuring the same. Any other suitable means may,however, be employed for retaining the cushion in the socket or holder.The spurs or projections are mounted on the ferrule to secure greatstrength and durability, and at the same time to avoid perforating theelastic block or cushion so that the durability and efficiency of thelatter will not be impaired.

The upper wall of the socket or holder is thickened and is provided atthe center with a threaded perforation for the reception of a lowerthreaded end 13 of a connecting rod 14, which is operated by a cam oreccentric 15. The connecting rod passes through the bore or opening 3 ofthe lower portion of the crutch and extends upwardly therefrom into thespace between the sides 16 of the upper portion of the crutch, and isconnected at its upper end with a strap or ring 17 of the eccentric orcam. The strapor ringis provided at the bottom with an enlargement orlug 18, having a threaded socket for the reception of the upper end 19of the rod, which is also threaded.

The cam or eccentric, which is circular, is provided with a peripheralgroove to receive the strap or ring 17, and it has eccentricallyarranged trunnions or pivot portions 20, which are journaled in suitablebearing openings 21 of the sides of a casing 22. The strap or ring issplit at the top, the terminals 23 of the split portion being extendedupwardly and connected together by a screw 24, which pierces one of theterminals and engages a threaded opening in the other.`

The casing, which conceals the cam or eccentric, is provided with sides,which are connected, at the top at 25, and it has suitable end walls 26,which are extended beyond the top and bottom of the casing and which areperforated for the reception of bolts 27, or other suitable fasteningdevices for securing the casing to the sides of the upper portion of thecrutch. The casing, which is arranged in the space between the sides ofthe upper portion of the crutch, is located a short distance below thehandle 28 of the crutch, and the latter is provided at a` point belowthe casing with a metallic cross piece 29, having a central perforationthrough which the connectinggod passes. The cross piece 29, which formsa guide for the connecting rod, has its terminals bent upwardly andsecured to the inner iaces of the sides of the upper portion of thecrutch by suitable fastening devices.

The cam is provided with a polygonal opening 30, extending through thepivots or trunnions and adapted to be engaged by a polygonal shank 31 ofa key 32. The shank 3l and the opening are preferably rectangular incross section, but they may be oi any other polygonal shape. The key,which is provided withV an enlarged body portion to form a handle orgrip, has a rounded projection or lug 33 extending from the body portionand arranged in parallelism with the shank and adapted to engage aspring actuated bolt 34 ot the cam. The cam is adapted to be rotated onehalt oi a revolution to either project thecushion l2 beyond the spurs orprojections, or to move the cushion upwardly within the guiding socketor portion 7 of the ferrule 4 to permit the spurs to project beyond it,and the said bolt 34 is adapted to engage upper and lower apertures 35and 36 oi the casing for locking the cam or eccentric in either of thesaid positions. The key, when inserted in the opening 30 ofthe cam oreccentric, is adapted to depress the bolt 34 by means oi the proj ection33, and when the bolt or projection, which has its outer end rounded, isslightly depressed, the key may be readily rotated to carry the boltbeyond the aperture. As soon as the bolt is brought opposite the otheraperture, it automatically springs outwardly and locks the cam oreccentric against further rotary movement. The bolt is provided at itsinner portion with a head, and is engaged by a spring 37, arranged in aperforation of the cam or eccentric and retained therein and inengagement with the bolt by means of a screw plug 39, one end of theopening 40 of the cam being interorly threaded to receive the plug. Theplug is provided at its outer end with a groove to receive the blade oia screw-driver for enabling it to be readily removed, Whenidesired.

The shank 3l oi the key is provided at its outer end with a threadedbore or socket 4l, adapted to be engaged by a screw 42 for retaining thekey in the opening of the cam or eccentric. A washer 43 is interposedbetween the head of the screw and the contiguous pivot portion ortrunnion, and the key may form a permanent portion of the crutch. Thekey, however, may be carried in the pocket and when it is desired torender the key detachable the screw 42 is removed.

Having thus fully describedmy invention, what I claim as new and desireto secure by Letters Patent, is:-

l. The combination of a crutch provided at the bottom with a socket,spurs or projections located at the Walls of the socket and havingShanks detachably secured to-the same, and a cushion mounted in thesocket and operable in the space between the spurs or projections.

. rotary cam or 2. The combination of a crutch provided at the bottomwith a socket having an enlarged lower end provided with threaded bores,spurs or projections having threaded shanks detachably secured withinthe said threaded bores, and a cushion movably mounted in the socket andarranged to project through thespace between the spurs or projections.

3. The combination of a crutch, means movably mounted at the lower endof the crutch for engaging the ground or other surface, a casing mountedon the crutch, a cam or eccentric arranged within the casing andconnected with the said engaging means, and a key-operated lockingdevice mounted on the cam and engaging the casing.

4t rlhe combination of a crutch provided at its lower end With`a sockethaving rigid surface-engaging means, a holder slidable in the socket, acushion secured in the holder and adapted to be extended beyond thesocket, a connecting rod secured at its lower end to the holder, andoperating mechanism connected with the upper end of the connecting rod.

5. The combination of a crutch having extensible surface-engaging means,acasing mounted on the `crutch and having opposite apertures, a rotarycam or eccentric mounted Within the casing and connected with the saidmeans, a locking device carried by the eccentric and arranged to engageeither of the said apertures of the casing, and a key for rotating thecam or eccentric, said key being provided With means for disengaging thelocking device from the casing.

6. The combination of a crutch having extensible surface-engaging means,a casing mounted on the crutch and having opposite apertures, a rotarycam or eccentric mounted Within the casing and connected with the saidmeans, a spring actuated bolt mounted on the cam or eccentric andarranged to engage either of the apertures of the casing, and a key forrotating the cam or eccentric provided with means for disengaging thebolt from the casing.

7. The combination of a crutch having extensible surface-engaging means,a casing provided with apertures, a eccentric mounted Within the casingand connected with the said means and having a threaded opening, a boltmounted within the opening for engaging the apertures of the casing, athreaded plug secured Within the opening of the cam or eccentric, aspring interposed between the plug and the bolt, and a key having aprojection to extend into the apertures of the casing to depress thebolt, said key being also provided with means for rotating the cam oreccentric.

8. The combination of a crutch having extensible surface-engaging means,a casing mounted on the crutch, a cam or eccentric provided withjournals mounted Within the casing and having a polygonal opening, alocking device carried by the cam oreccentric for engaging the casing,and a key having a polygonal shank to engage the opening of the cam oreccentric and provided With means for operating the locking device torelease the said cam or eccentric.

9. The combination of a crutch having extensible surface-engaging means,a cam or eccentric for operating the same, locking means for holding thecam or eccentric, a key for rotating the cam or eccentric provided withmeans ifor rotating the locking device, and means for detachablysecuring the key to the cam or eccentric.

In testimony that I claim the foregoing as my own I have hereto affixedmy signature in the presence of two Witnesses.

I-I. L. DARLINGTON, J. C. LIGnrNnR.

